This type of aromatic substance for filter cigarettes is directly added to shred tobacco or filter fibers of filter cigarettes. Alternatively, it is applied to an inner wrapper for wrapping cigarette bundles. For example, U.S. Pat. No. 3,906,893 discloses an apparatus for fabricating an inner wrapper, namely web, to which menthol is applied.
More specifically, the web is obtained by laminating aluminum foil to be faced to the outside and a paper layer to the inner side. According to the apparatus disclosed in the U.S. patent, liquid menthol as an aromatic substance is applied to the back of the web delivered from a feed spool, and is infiltrated into the paper layer. The apparatus subsequently winds the web infiltrated with the aromatic substance around a take-up spool to form a web roll for inner wrapper.
In the case that the above-mentioned web roll is used in a machine for wrapping cigarette packages, namely an apparatus for feeding the inner wrapper, the web is guided along a feeding path from the web roll to a cutting position, where the web is cut into an inner wrapper with the given length. Thereafter, the packing machine wraps the cigarette bundle in the inner wrapper to form an inner pack, and then further wraps the inner pack in outer wrapper to form a cigarette package.
If the aromatic substance is infiltrated into the paper layer of the inner wrapper as described, fragrance components vaporized from the aromatic substance are absorbed into the filter cigarettes in the inner pack, thereby giving the additional aroma to the filter cigarettes.
When the web infiltrated with the aromatic substance is in the form of the web roll, the aromatic substance is transferred from the paper layer to the outside face of the web, namely aluminum foil, adjoining the paper layer. Therefore, when the web is drawn from the web roll to the cutting position, the aromatic substance adheres to guides, such as lots of guide rollers and guide plates for forming the feeding path, which smears the guides. Especially the aluminum foil is smoother than the paper layer, so that it is more liable to smear the guides with the aromatic substance, compared to the paper layer.
When the guides are smeared with the aromatic substance, the web is likely to slip or meander. In this event, the forming and feeding of the inner wrapper in the feeding apparatus are not properly carried out, which causes defectiveness in fabrication of the inner packs in the packing machine. In the worst case, the web transfer itself becomes impossible, and the packing machine even comes to a halt.